In recent years, with enhancement of properties and downsizing of image pickup apparatuses employing a solid-state image pickup element such as an imaging sensor of CCD (Charge Coupled Devices) type and an imaging sensor of CMOS (Complementary Metal-Oxide Semiconductor) type, cell phones and personal digital assistants equipped with such the image pickup apparatuses are coming into wide use. Further, as for image pickup lenses built in the image pickup apparatuses, enhancement of properties corresponding to increasing the number of pixels of an image pickup element is requested, while demands for furthermore downsizing is increasing.
As an image pickup lens for such the use, there is provided an image pickup lens with five-element structure, because its properties can be furthermore enhanced in comparison with a lens with a three-element or four-element structure.
As an image pickup lens with the five-element structure, an image pickup lens composed of in order from the object side, first lens with positive refractive index, second lens with negative refractive index, third lens with positive refractive power, fourth lens with negative refractive power, and fifth lens with negative refractive power is disclosed (For example, in Patent Literature 1).
Further, an image pickup lens composed of, in order from the object side, first lens with negative refractive index, second lens with positive refractive index, third lens with negative refractive power, fourth lens with positive refractive power, and fifth lens with negative refractive power is disclosed (For example, in Patent Literature 2).